1. Field of the Invention
The invention relates to a device for and a method of processing biometric data.
2. Description of the Related Art
From European Patent EP 0 372 762 B1, a procedure for processing biometric data is known which involves a comparison of several characteristic points (minutiae) allocated to the respective finger print images, serving to identify a finger print. A finger print sensor detects several finger print images and determines the minutiae in the form of digitized data. This procedure is applied to two consecutive finger prints. To determine whether the finger prints are identical, the minutiae of the first finger print and of the second finger print are compared with each other. If the number of identical minutiae is higher than a preset threshold value, the finger prints are assumed to match. The disadvantage of this procedure is that the finger prints serving as a reference are stored without protection in a processing unit of the device, so that manipulation and tampering of the finger print data is possible.
From German Publication DE 44 39 593 C2, a device for processing biometric data is known which provides for evaluation and/or comparison of biometric data in a chip card. This lowers the danger of manipulation and/or unauthorized use of data, because the data serving as reference does not leave the chip card.
From German Publication DE 196 18 144 C1, a device for processing biometric data is known in which biometric data allocated to a certain person are stored as reference data on a portable identification element. These reference data are verified for agreement with identification data which are supplied through a sensor. In this process, the identification data are determined on the basis of the biometric input signals of the sensor. The disadvantage of the known device is that the sensor is integrated in the portable identification element. This involves a sophisticated card design, which leads to a considerable increase in the manufacturing costs for these cards. Due to the fact that the sensor is closely interlocked with the material of the card, replacement of a defective sensor or upgrading to an enhanced sensor is impossible.
Thus, the object of the present invention is to process biometric data while ensuring data safety during the evaluation of biometric data in a simple manner.
To solve this task, a device according to the invention comprises: a processing unit and an identification element which stores reference data. The processing unit further comprises: a sensor to detect a biometric input signal; and a processor for processing said input signal to create identification data. A comparison program checks for a match between the reference data and the identification data. The comparison program is divided into a first part running on the processor and a second part running on the identification element.
In one embodiment, the identification element is portable. The identification element may comprise a semiconductor component, and the second part of the comparison program may be set to run on the semiconductor component.
In a further embodiment, at least a portion of the identification data and the reference data are processed in the second part of the comparison program running on the semiconductor component.
In a further aspect of the invention, the first part and the second part of the comparison program each comprise at least one verification step. Preferably, the last of the verification steps is performed in the semiconductor component, and a confirmation signal is emitted from the semiconductor component to the processing unit in case of a positive result.
In yet a further aspect of the present invention, the comparison program comprises a comparison of similarities in which parameter-dependant comparative values are compared with a pre-set threshold value for decision. The threshold value is preferably stored in at least one of a protected memory area of the identification element and the processing unit.
In a further aspect of the invention, weighted comparative values are formed in the first and the second parts of the comparison program, and a confirmation signal may be transmitted from the identification element to the processing unit when a total of comparative values exceeds the threshold value for decision.
In a yet further embodiment of the invention, an alignment between the identification data and the reference data is performed in the processing unit before the comparison program checks for a match. Only a portion of the reference data may be transferred from the identification element to the processing unit for the alignment.
By way of example, the sensor may be an optical, thermal or electronic sensor.
In a yet further embodiment of the invention, the identification element is a chip card comprising a microprocessor. The microprocessor may further comprise: a semiconductor component; and a contact area, the contact area being flush with a surface of the card. A card reader for reading from and writing to the semiconductor component may be integrated into the processing unit.
A confirmation signal generated by the identification element may be provided with an electronic signature.
A method according to the invention comprises the steps of: detecting at least one biometric input signal; creating identification data from the input signal; transmitting the identification data to an identification element; comparing the identification data with reference data, the reference data being stored in the identification element and the comparing being based on parameters; and emitting a confirmation signal, the confirmation signal being a function of a result of the step of comparing.
A further embodiment of the method may also comprise a step of aligning of identification data to reference data that is performed before the step of comparing.